Yeah we all know why Alabama's up there at the top, but I'm definitely surprised to see Auburn but not A&M. Aside from any local fan bases, it seems like both should have picked up a similar sort of "halo effect" from playing in the SEC West through those years.
From those 18, the New SEC has 8 teams, the New B1G has 7, and then the ACC has Clemson and FSU, with ND being independent(ish).